What is "fake"? Everything in the OP's list, except may be no. 6, is pure and legit marketing.
I'd like to say this concerning #6. As someone who writes web content on behalf of other companies to earn part of my income, the matter of this author tag is nonsense. Historically offline they were known as ghost writers, and still are.
If someone hires me to write an article or a series of articles as far as I'm concerned once I hand it over to them they OWN it. They can attribute it any way they want. They paid for that right. I have no desire or ego to appease that needs to have it attributed to me.
Large companies might have many such writers they tap for content. Some companies may want to attribute it to a guest writer while others may not, it's their choice. Still larger ones probably have in-house writers. The content those writers produce will often times outlive the employee's tenure at that company. It makes perfectly good sense to attribute all writing to one author or even the company itself.
And don't make the mistake of thinking that because it was written by someone other than the person presenting it as theirs that it's any less authoritative. I write on a very wide swath of topics of interest and most of the time I have to spend a few hours, sometimes a day, interviewing the person that I'm writing on behalf of. It's not my knowledge, I'm only doing my best to express their objectives in a creative manner -- something that might not be one of their strong points. Right now for example I'm writing about accounting, bookkeeping, and personal income taxes -- YUCK, with a capital YUCK. But it won't be apparent to the reader because I am simply putting the owners passion into creative words -- that part I do enjoy. It's like bringing his passion to life and giving it a personality through imagery. I love that type of challenge.